Co-axial restraint for connectors within flip-chip packages
AssigneeInternational Business Machines Corporation
InventorsMukta G. Farooq, John A. Fitzsimmons
Life of this patent
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Abstract
An assembly can include a microelectronic element such as, for example, a semiconductor element having circuits and semiconductor devices fabricated therein, and a plurality of electrical connectors, e.g., solder balls attached to contacts of the microelectronic element. The connectors can be surrounded by first, inner regions 200 of compressible dielectric material and second, outer regions of dielectric material. In one embodiment, an underfill can contact a face of the microelectronic element between respective connectors or second regions. The second regions can provide restraining force, such that during volume expansion of the connectors, the first regions can compress against the restraining force of the second regions.
Claims11
A method of fabricating a microelectronic assembly, comprising:
- forming a plurality of electrically conductive connectors extending away from a face of a microelectronic element, each of the connectors having a surface facing away from the face of the microelectronic element;
- forming compressible dielectric first regions contacting the surfaces of the connectors and surrounding the connectors;
- forming compressible dielectric second regions surrounding the dielectric first regions;
- and
- forming third regions surround the dielectric second regions, wherein the first regions are more compressible than the second regions and the second regions are more compressible than the third regions.
Dependencies are inferred from the claim text.